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WS NO2 - Nitrite



Naturally occurring nitrifying bacteria detoxify nitrogenous wastes using biological filtration. One type of bacteria (Nitrosomonas spp.) converts ammonia to nitrite while another naturally occurring bacteria (Nitrobacter spp.), converts the nitrite into a far less harmful form of nitrogen waste: nitrate.


Nitrite is the extremely toxic intermediate stage for fish and invertebrates. As the level of nitrite increases, the function of hemoglobin necessary for the transport of oxygen in fishes` blood gets blocked. Lethal concentrations cause chronic stress which lowers the fish`s resistance to parasite and bacterial attacks, reducing food intake and growth, and can result in death. It also causes damage to fishes` natural barriers and can stimulate cancer in the digestive system.


Nitrite levels in excess of 0.1 mg/L are considered dangerous to many ornamental fish. For invertebrates, levels higher than 0.05 mg/lt are toxic. If the biological filtration process is impeded, for example by new filter material, this can lead to harmful rise in the nitrite ion concentration. For this reason, regular use of a nitrite test kit is an absolute requirement.




  • Easy reading: “RealColor” technology.
  • High precision: thanks to the use of calibrated droppers
  • NIST validation: each batch of elos reagents is validated using NIST(National Instituteof Standardand Technology) samples
  • "Safereagents": reagents and testing procedures are based on Low Risk Reagents. None of our test kits are based on Toxic Reagents.
  • The ELOS AquaTest NO2, developed for both fresh water and marine aquariums
  • Allows the determination of the Nitrite level with the help of a finely tuned color scale which shows a range of 0-2 mg/Lt

ELOS AquaTest NO2, as well as all the other colorimetric test kit of this line, grant very high precision thanks to several procedures like the use of “RealColor” technology, an accurate system to calibrate the color chart compared to the reagents; the validation of each reagent with NIST (National Institute of Standard and Technology) certified samples and the careful stock management to supply to our customers ONLY the freshest production batch. 

WS NO2 - Nitrite

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